Various types of hub-to-shaft connections are known in which clamping bolts, arranged uniformly circumferentially around a clamping ring, provide for axial movement of clamping cones to cause radial pressure being placed between a hub and a shaft, and thus provide for engagement of the hub and the shaft for transmission of torque. Clamping connections of this type are described, for example, in German Pat. No. 1,099,806, to which, roughly, U.S. Pat. Nos. 3,679,247 and 3,847,495 correspond. Clamp connections of this type have the advantage with respect to other clamping connections that there is no shifting of the inner and outer clamping rings on the shaft, or in the bore of a hub, respectively, when the connection is being tightened. Thus, exact alignment and angular adjustment of the hub with respect to the shaft is possible. Since no axial shifting occurs between the hub, the shaft, and the clamping cell upon tightening, the frictional forces are also decreased so that, in effect, only those forces within the clamping cell which arise between the clamping rings and the operatively connected double-conical clamping rings will be applied, and all the forces will be available for transmission of torque. The only force which has to be overcome, thus, is frictional force at the clamping side. The angles of the conical clamping rings are so selected that they are above the self-retaining angle so that the clamping set can be loosened after release of the axial clamping forces, that is, after loosening of clamping bolts.
One type of clamping set which has been found particularly useful is the spring ring clamping set. One disadvantage has been noted, however, that it can be used only to attach a shaft to a rotary element which is formed with a hub. Other connections, for example to directly connect a hollow shaft to a rotary element, or a projecting hub portion on a shaft, cannot be secured by this set. A spring ring clamping set cannot be used, for example, with a hollow shaft, or in a cylindrical blind bore of a shaft which is to be spread over a rotary element since the axially slit thin-walled conical clamping rings cannot accept the radial forces which arise upon clamping. If the clamping set is to be used externally on a projecting stub of a rotary element which is to be compressed over a shaft, such spring ring clamping sets likewise cannot be used since the radial tension forces which arise cannot be accepted by the axially slit thin-walled conical outer rings. It is thus necessary to have different types of clamping sets for various specific uses; this is expensive, requires stocking of many different parts, and thus is uneconomical. Clamping rings of these types are, therefore, primarily suited for direct hub-to-shaft connection of standard sizes in which large quantities can be made. Clamping systems of this type are shown in the aforementioned German Pat. No. 1,009,806, to which U.S. Pat. Nos. 3,679,247 and 3,847,495 generally correspond; and in German Pat. No. 1,294,751, to which U.S. Pat. No. 3,972,636 corresponds, as well as in German Pat. No. 2,147,501, to which U.S. Pat. No. 3,776,651 corresponds.